I've encountered a strange problem: Somehow the FTB Launcher stole the profile and install folder location from my roommate's computer the first time I launched it, account information and all. I'm honestly at a loss of how this could have happened, seeing as this was the first time I've ever launched FTB and my roommate has never used his Minecraft account on my computer. Both computers are hooked up to the same router, but other than that are unconnected. I haven't been able to figure out of this is reproducible because FTB appears to have files installed somewhere I don't know where to find it, as it still has my account information if I delete the launcher and the install folder.